Rotatable hollow-head debarker mounting flexible bark-removing elements



Filed Feb. 26, 1945 J. ASTRQM ROTATABLE HOLLOW-HEAD DEBARKER MOUNTING FLEXIBLE BARK-REMOVING ELEMENTS 5 Sheets-Sheet l Dec. 4, 1951 J. As'rRbM 2,576,912

ROTATABLE HOLLOW-HEAD DEBARKER MOUNTING FLEXIBLE I BARK-REMOVING ELEMENTS Filed Feb. 26, 1945 3 Sheets-Sheet 2 Dec. 4, 1951 s b E 2,576,912

ROTATABLE HOLLOW-HEAD DEBARKER MOUNTING FLEXIBLE BARK-REMOVING ELEMENTS Filed Feb. 26, 1945 5 Sheets-Sheet :5

Patented Dec. 4, 1951 ROTATABLE HOLLOW-HEAD DEBARKER MOUNTING FLEXIBLE BARK-REMOV- IN G ELEMENTS Johan Astriim, Nyhamn, Sweden, assignor to Svenska Cellulosa Aktiebolaget, Stockholm, Sweden, a corporation of Sweden Application February 26, 1945, Serial No. 579,749 In Sweden March 1, 1944 8 Claims. (01. 144208) longitudinal portion of the chain is constantly kept in contact with the log during the treatment of the latter, because a layer of bark is retained between the chain portion in question and the log itself, which layer, while maintaining the desired barking effect of the chain, protects the wood behind the bark, so that said wood is spared as far as possible, only the bark itself being removed.

According to the present invention this object is attained by having the chain or chains, etc.

fixed in a rotatable supporting device having an opening extending therethrough for forward feeding of the log centrally through said supporting device. The chains etc. are so arranged in said opening that each chain or the like is engageable in its longitudinal direction with the log being fed and is adapted, during the treatment of said log, to be retained with substantially one and the same longitudinal chain portionin uninterrupted contact with the log. The supporting device in question preferably comprises two elements, which can be connected up to a driving device, the barking chain (or chains) being fixed to said elements in such a manner that said chain (or chains) can be drawn tight against the log by the two elements referred to being movable relatively to one another and, after the tightening of the chain, being movable as a single unit in the course of the bark-removing or decortication process. The two movable elements in question can be suitably locked together after the tightening of the chain against the log, and can comprise rotatably arranged coaxial rings or the like, to which the barking chain is so fitted that in the inactive position it extends across the inner ring opening through which the log can be fed. In that case, the barking chain will be situated somewhat laterally of the geometrical axis of the rings. One of the rings connected to the driving device can be arranged upon its rotation to carry along the other ring which, for the achievement of the relative motion between the rings, can be acted upon by a braking device or the like. The driving device is preferably. connected to the inner ring, which by a hub or the like is fitted in bearings, and the outer 'ring is mounted on the inner. The barking chain can also be resiliently or yieldingly fastened, either at one or both ends. When a plurality of barking chains are employed, they can either cross one another or be spaced in the longitudinal direction of the log.

The barking machine according to the invention features a high bark-removing capacity, but the machine itself is of such dimensions that it can easily be transported from log pile to log pile. Furthermore, the machine according to the invention satisfactorily complies with the obvious requirement that only the bark proper, and thus none of the wood, is removed from the log upon decortication. By reason of its extremely simple design the machine is not only inexpensive to manufacture, but also easy to operate for carrying out the bark-removing process. In the event of any replacement of the chain (or chains) being necessary during the actual work, this operation can be effected verypromptly and Without any interruption of operations, worth mentioning, being necessary.

The invention is illustrated in the accompanying drawing, where Figs. 1-4 represent side elevations of one embodiment of the machine with several barking chains crossing one another. Fig. 1 represents the chains in their inactive position, Fig. 2 at the commencement of their tight ening around the log, Fig. 3 in the position where they are partially tightened up and Fig. 4, fully tightened. Figs. 5 and 6 are side elevations of that embodiment of the barking machine according to the invention, having only one barking chain, where Fig. 5 shows the chain in the inoperative position and Fig. 6 shows the chain tight= ened around the log. Fig. 7 shows a vertical section through an embodiment of the machine provided with only one chain. Fig. 8 represents a vertical section through part of a modification having several barking chains spaced. in the longitudinal direction of the log. Fig. 9 represents a perspective view of the embodiment shown in Figs. 1-4.

Referring to the drawings, l indicates the outer ring and 2 the inner ring respectively. One or more bark-removing chains 3 are at one end fixed to the ring l and at the other end to the ring 2, in such a manner that the chain or chains in the inactive position extend across the inner ring opening. As will be seen from the drawing, the chain or chains 3 are situated somewhat laterally oi the geometrical axis of the rings fl 3 and 2. The chains 3 are so arranged as to be resilient or yielding, which, as shown, is suitably achieved by each chain being fixed to the outer ring I by a spring 4. The log 5 isfed forward through the inner ring-opening in such a manner that the axis of the log approximately coincideswith the geometrical axis of the rings I and 2. The outer ring I which is mounted on the inner ring 2 and is carried along thereby on rotation, can be braked by mean of a suitable device, so that the inner ring moves a little relatively to the outer for tightening the chain or chains 3 around the g 5. When the inner ring 2 has turned relatively to the outer ring I through the angle necessary for the tightening of the chain or chains, it is possible by means of a looking device, for instance a pin 6 which extends through an opening in the ring I into an opening in the ring 2, to lock the rings I and 2 to one another, whereupon there will no longer be any necessity for actuating the brake in order to maintain the desired relative position of the rings upon their continued rotation when decortication takes place. For braking the outer ring I, a brake-block I can be employed, which is connected to a lever 9 movably mounted on a rocking support 8. The chain or chains 3 are fixed to the rings I and 2 by pins III. The inner ring 2 is provided with a hub II which is fitted in bearings I2 and has a belt pulley I3, which can be driven from a suitable driving pulley I8 through a belt I6 (Fig. 9). The forward feed movement of the log 5 is eifected by means of rollers I5 (Fig. 9).

In accordance with Figs. 1-4, four barking chains 3 extend between the fixed points A-B, C-D, E-F and G-H. These chains are so arranged that two of them cross the other two. In Fig. 1 the chains occupy an inactive position, the two rings I, 2 rotating together as a single unit. If now the outer ring I be arrested by actuation of the brake device I, 8, 9, the inner ring 2 connected up to the driving device will, however, move relatively to the outer ring so that the chains are tightened around the log. The arrows in Figs. 2-4 indicate how, for example, the fixed point E on the inner ring is moved more and more in relation to the outer ring, until it reaches the position shown in Fig. 4. In like manner, the fixed points A, C and G of the chains are moved relatively to the outer ring. When the chains 3 have thus been caused to cocupy the position shown in Fig. 4, the rings I, 2 are locked to one another by means of the pin 6 so that it is not necessary to apply the braking device during the ensuing bark-removing operation. When a log has been stripped of its bark, the locking of the rings is released by withdrawing pin 6 from the position shown in Fig. 4 to the position shown in Figs. 1, 2 and 3 whereby the tensioned springs 4 automatically cause the outer ring to return to the initial position, and the chains again assume their inactive position. The springs 4 also permit the chains 3 to yield when the pressure exercised by the log being fed through, due, for example, to excrescences thereon, exceeds a, certain value.

When only one chain 3 is employed, the outer ring I can be braked in the same way as described above, whereby the fixed point A of the chain on the inner ring is shifted from the position indicated in Fig. 5 into that position for example as shown in Fig. 6. The two rings I and 2 are then locked together by means of the pin 6, and the braking device is relaxed.

In accordance with Figs. 7 and 8 the chains 3 can be fixed to the outer and the inner ring in such a manner, 1. e. by means of pins I0 and I0 (Fig. 7) and by'means of pins I4 and I1 (Fig. 8), that the chains are initially inclined to a plane which is perpendicular to the longitudinal axis of the log. Also, as shown in Fig. 8, two or more chains may be spaced in the longitudinal direction of the log, so as to act in tandem.

In all of the shown embodiments the chain etc. will engage the log in the longitudinal direction of said chain, and, during the treatment of the log, will be retained with substantially one and the same longitudinal chain portion in uninterrupted contact with the log.

The devices as illustrated and described may of course be modified in various respects without departure from the idea fundamentally characterizing the invention.

What I claim is:

1. A barking machine comprising means for axially moving a log to be debarked, a structure rotatable about said log axis, means engaging and rotating said structure, at least one flexible member secured at spaced points thereof to said structure, and means for yieldably tensioning an intermediate portion of the flexible member against the log, said structure comprising two relatively rotatable and concentric rings, an end of .the flexible member being attached to each ring, and the means for tensioning the flexible member against the log including means engaging one of the rings to cause said relative rotation between said rings.

2. A barking machine comprising means for axially moving a log to be debarked, a structure rotatable about said log axis, means engaging and rotating said structure, at least one flexible member secured at spaced points thereof to said structure and means for yieldably tensioning an intermediate portion of the flexible member against the log, said structure comprising two coaxial rings, an end of the flexible member being attached to each ring, the means for rotating the structure being directly connected to only one of said rings and the machine comprising a brake engageable with the other of said rings to rotate said rings with respect to each other so as to vary the angular distance between the ends of said flexible member.

3. A barking machine comprising means for axially moving a log to be debarked, a structure rotatable about said log axis, means engaging and rotating said structure, at least one flexible member secured at spaced points thereof to said structure, and means for yieldably tensioning an intermediate portion of the flexible member against the log, said structure comprising two parts which are relatively movable in circular concentric paths around said log axis and an end of the flexible-member being attached to each of said parts.

4. A barking machine comprising a first annular member having an opening therein and mounted to rotate about an axis lying within said opening, a second annular member mounted on said first member for rotation relative thereto or therewith as a unit about said axis, said second member having an opening therein embracing said axis, means engaging and rotating one of said members, means engageable with the other of said members to cause said relative rotative movement, means engageable with both members and locking said members together for said rotation as a unit, means for feeding a log through the openings in said members, and at least one flexible member having one of its ends attached to the first annular member and its other end attached to the second annular member and an intermediate portion extending across said openings.

5. A barking machine as defined in claim 4 comprising a plurality of flexible members each having one end thereof attached to the first annular member and the other end attached to the second annular member and an intermediate portion extending across said openings.

6. A barking machine as defined in claim 4 comprising a plurality of flexible members each having one end attached to the first annular member and the other end attached to the second annular member and an intermediate portion extending across said openings, at least two of said flexible members crossing each other.

7. A barking machine as defined in claim 4 comprising a plurality of flexible members each having one end attached to the first annular member and the other end attached to the other annular member and the intermediate portion extending across said openings, said flexible members being positioned in different planes longitudinally of the axis of said annular members.

8. A barking machine comprising a tubular member mounted for rotation about its longitudinal axis, a ring concentric with said tubular member and carried by one end thereof for rota- 0 tion about said axis, means engaging and rotating said tubular member, means engageable with said ring to cause relative rotative movement thereof with respect to said tubular member, a flexible member having one end attached to said ring and the other end attached to said tubular member and an intermediate portion extending across the opening in said ring and tubular member, and means for feeding a log to be debarked through said opening.

JOHAN AsTRoM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,243,294 Hruska Oct. 16, 1917 1,353,370 Williams Sept. 21, 1920 1,462,415 Kober July 17, 1923 1,539,603 Saprones May 26, 1925 1,887,908 Tidblad -1 Nov. 15, 1932 1,899,379 Adams Feb. 28, 1932 1,937,073 Stuve Nov. 28, 1933 2,005,799 Nicholson et al June 25, 1935 2,193,971 Laurent Mar. 19, 1940 2,213,923 Stuart Sept. 3, 1940 FOREIGN PATENTS Number Country Date 161,366 Switzerland July 1, 1933 

